Circulating pump arrangements



Dec 26, `1967 RWEINSTEIN 3,359,911

-CIRCULATING PUMP ARRANGEMENTS Filed Feb. 2l, 1966 2 Sheets-Sheet l n /N VENTO/a R/CHARD wE//vs 'rE/N ATTOR/V KS De 26, .1967 R. wf-:lNsTElN v CIRCULATING PUMP ARRANGEMENTS 2 Sheets-Sheet 2 Filed Feb. 2l, 1966 /NVENTOR ,fe/CHAR@ wE//vs-rE//v Br D $55? B ii Lug/1 -To NEV United States Patent O M 3,359,911 CIRCULATING PUMP ARRANGEMENTS Richard Weinstein, Huntington, N.Y., assigner to Flair Manufacturing Corp., Hauppauge, NX. Filed Feb. 21, 1966, Ser. No. 528,883 9 Claims. (Cl. 10S-87) ABSTRACT F THE DISCLOSUR A circulating pump useable, for example, Ias a circulator for a hydr-onic heating system having an impeller with an elongated impeller shaft which extends from the impeller housing through a hollow drive shaft such as the hollow drive shaft of an electric motor and is turnable with respect thereto. The ends of the impeller and drive shaft are resiliently connected, for example by means of a coil spring at their end portions distal from the impeller. A seal is provided for the pump having a pair of sealing elements such as sealing rings in sealing engagement. One of the elements is connected to the impeller shaft to be pressed in tighter sealing engagement with the other by the resilient connection between the impeller and drive shaft-s. This resilient connection is preferably a coil spring which is wound in the direction of rotation of the impeller so as to initially relieve sealing engagement of the sealing elements lowering the initial starter torque required.

This invention relates to an improved circulating pump arrangement. The invention more particularly relates to an improved circulator arrangement for a hot water or hydronic heating system.

Hot water or hydronic heating systems generally provide for the circulation of water through a boiler orgiother heaters to the radiators or other heating elements and back to the heater. The water is generally caused to circulate through this closed system by means of a circulator which consists of a housing having an impeller, generally in the form of a paddle wheel. T-he impeller has a shaft connected thereto which extends through its housing and an electric drive motor is mounted on a frame adjacent the impeller housing with its drive shaft coaxial with the impeller shaft. The ends of the impeller shaft and the drive shaft are resiliently connected, as for example by means of a stretched flat wire spring. Most commonly, the circulator is mounted on the return side of the boiler and the electric motor is controlled through a relay by a thermostat positioned in the area being heated. The seal where the impeller shaft extends through the hou-sing is generally formed by a pair of seal rings, one of which is rotatably connected to the impeller shaft or impeller, and the other sealed around the opening through the housing Vfrom which the impeller shaft extends. The stretched spring between the motor drive shaft and the impeller shaft press the sealing surfaces of the seal rings in sealing contact.

The compactness of the prior art arrangements was limited, particularly in its axial dimension, in that adequate room had to be provided between the motor and the impeller housing for the shaft and spring arrangement and to allow adjustment of the spring to compensate for seal wear. Ofter in the prior art arrangements an excessive starting torque was required in order to insure sliding contact between the seal surfaces, so that a larger motor would be required than would be necessitated by the normal running operation. This prior art arrangement is also difficult to install and service.

One object of this invention is an improved circulator pump arrangement which overcomes the above mentioned prior art disadvantages.

3,359,911 Patented Dec. 26, 1967 A further object of this invention is a circulating pump arrangement which may be made more compact than the prior art devices.

A further object of this invention is a circulating pump arrangement which requires less starting torque than the prior art arrangement-s.

A still further object of this invention is a circulating pump arrangement which is less expensive than the prior art arrangements and which may be mo-re readily installed, adjusted and serviced.

These and still further objects will become apparent from the following description read in conjunction with the drawing in which:

FIG. 1 is a side elevation partially in sections of an embodiment of a circulating pump in accordance with the invention;

FIG. 2 is a perspective phantom view of the circulator shown in FIG. I.

The circulator pump in accordance with the invention has a housing and a rotatable impelle-r of the well known conventional struction. The impeller has, however, an elongated impeller shaft which extends through the length of the entire unit including the drive arrangement. A hollow drive shaft is rotatably mounted adjacent the housing coaxial with the impeller shaft, with lthe impeller shaft turnably extending therethrou-gh, with the ends of the impeller and drive shaft being resiliently connected together. Preferably the drive shaft is a hollow drive shaft of an electric motor mounted adjacent the housing, and the distal ends of the drive shaft of this electric motor and of the impeller shaft which extends therethrough are connected by means of a coil spring which winds in the direction of rotation. Most preferably the coil spring is connected to the end of the impeller shaft by means of a nut which is adjustably threaded onto the shaft.

Preferably the housing is provided with a sealing ring arrangement having a pair of seal rings in face-to-face engagement coaxially positioned with respect to the impeller shaft. The ring closest to the impeller is connected to the impeller and/or its shaft, and the other ring is sealed to the housing around the opening through which the shaft extends.

Referring to the embodiment shown in the drawing, 1 represents the circulating pump housing having an inlet at one end provided with a bolt-on connection flange 2 and an outlet at the other end provided with a bolt-on connection ange 3. Rotata-bly mounted in the housing 1 is the impeller 4 which, in addition to its rotary motion, has a limited amount of free axial play. The impeller 4 has the bearing ring 5 connected thereto which turns in a corresponding annular recess in the front wall of the housing. The elongated impeller shaft 6 is connected to the impeller 4 for rotation therewith and extends through the front face of the housing 1. A seal ring 7 is coaxially positioned with respect to the impeller shaft 6 and impeller 4, and is seated in the bearing ring 5 for rotation with the impeller shaft and impeller. A seal ring 8 is seated around the opening through the front face of the housing 1 coaxial with the impeller shaft 6, so that it is in face-to-face sealing engagement with the seal ring 7.

The circulating pump so far described is thus of the well known and conventional construction except for the extended length of the impeller shaft 6. 'Ihe housing 1 thus has the conventional shape and dimensions and is constructed of conventional materials, as is the impeller and the seal rings 7 and 8. The seal ring 7, for example, may be made of graphite and the seal ring 8 of a ceramic material or stainless metal, such as stainless steel or Monel. Mounted in front Iof the housing 1 on the frame arrangement 9 is a fractional horsepower electric motor 10, as for example a 1A or 1A; horsepower, single phase, 110

volt, 60 cycle AC motor. This electric motor 10 is of conventional construction except that the drive shaft 11 is a hollow tubular drive shaft. The impeller shaft 6 extends coaxially through the hollow drive shaft 11 and may rotate with respect thereto. The distal end of the impeller shaft 6 is threaded at 12 and a castle adjusting nut 13, which may be secured by cotter pin 14, is screwed thereon. The distal end of the drive shaft 11 has a stop ring seated therein. A coil spring, such as a steel coil spring 16, is positioned around the impeller shaft y6 and extends between the nut 13 and stop ring 15. One end of the spring 16 is secured to the nut 13, as for example by extending in the bore hole 17, and the other end is secured to the drive shaft 11 by extending, for example, into the slot 17a. The forward end -of the electric motor 10 has a ange 18 with an extending annular shoulder 19, whichl slidably fits into a corresponding recess in the face of the housing 1. The rear end of the electric motor 10 is secured in the clamp 20 which is connected by a bracket 21 to the slide rods 22 of the frame 9 and secured in place by the set screw 23.

In operation the circulating pump is connected in the line of a hydronic heating system in the conventional manner by bolting the connection flanges 2 and 3 to corresponding ilanges in the line, the circulating pump generally `being positioned to circulate water therethrough into the boiler of the hydronic system, The electric motor 10 is connected to the control arrangement of the hydronic system in the conventional manner, as for example to a source of electric current which is switched on and off by a relay, `which in turn is controlled either directly 4by a thermostat in the area being heated, or indirectly by this thermostat through a zone control valve. Thus, when heat is called for, the motor 10 is energized and when heat is no longer called for, the motor 10 is deenergized. As the motor 10 is energized, the drive shaft 11 rotates, The torque is transmitted through the spring 16 to the impeller shaft 6, rotating the impeller and causing the circulation of the fluid through the pump. The spring 16 is coiled in the direction of rotation of the drive shaft 11 and its compression is so adjusted as t-o urge the impeller shaft 6 and impeller 4 in the direction toward the motor 10, and thus press the seal rings 7 and 8 in sealing contact with each other. As the motor 10' is initially energized and the drive shaft 11 starts to rotate, the spring 16 tends to wind up, thus reducing the force with which the seal rings 7 and 8 are pressed in face-to-face contact and allo-wing an initially easier rotation of the unit. Additionally in winding up the spring 16 the motor can obtain a running start, so that a substantially lesser starting torque is required. The seals 7 and 8 may have a tendency to bind after a period of nonuse, and this winding up of the spring 16 and the relieving of the pressure therebetween tends to free this binding and thus again reduces the starting torque required by the motor and tends to prevent the overloading of the motor. Furthermore, if some soil becomes embedded between the faces of the seal rings 7 and 8, causing a leakage, the

`same may be simply cleaned by tapping the free end of the impeller shaft 6, which tends to compress the spring 16 and axially move the impeller shaft 6 and the impeller '4 in a direction away from the electric motor 10, causing a corresponding movement of the seal ring 7 away `from the seal ring 8 and allowing water to pass therebetween, flushing out the soil.

Maintenance of the unit is greatly simplified in that wear of the seal rings 7 and 8 may be quickly compensated for by a simple removal of the cotter pin 14 and an adjustment of the adjusting nut 13, followed by a replacement of the -cotter pin 14. The entire electric motor unit may be very quickly and readily removed for servicing or repair by removing the pin 14 and nut 13, loosening the set screw 23, and sliding the entire motor unit with the frame 21 rearwardly, so that the frame 21 slides olf the slides 22. The motor may be very quickly reassembled by the reverse procedure. Due to the fact that the motor unit llt) is positioned right up against the housing 1 and no coupling is required therebetween as in conventional units, the axial length of the entire unit may be greatly shortened and may, for example, be less than onehalf the size of the conventional units, which is of extreme importance in many installations. The size may further be reduced by a corresponding reduction in the size of the electric motor 10, which may be made smaller due to the lower starting torque requirements. The spring and seal pressure may be very carefully adjusted from the rear with the use of a pressure gauge pressing against the rear end of the impeller shaft 6. The construction furthermore is greatly simplified and less expensive than the conventional units.

While in the embodiments shown the electric motor 10 is coaxially positioned with respect to the impeller and impeller shaft, it is also possible to provide an arrangement with any hollow drive shaft corresponding to the drive shaft 11. Thus, for example, a bearing mounted drive shaft 11 may be used, which is provided with a belt-type pulley driven from an offset motor. Conversely, the drive shaft 11 may be driven by any other offset drive arrangement, such as a gear arrangement. Thus, while the invention has been described with reference to the specic embodirnents shown, various changes and modifications which fall within the spirit of the invention will become apparent to the skilled artisan. The invention therefore is only intended to be limited by the appended claims or their equivalents wherein I have endeavored to claim all inherent novelty.

What is claimed is:

1. A circulating pump comprising a housing, an impeller rotatably mounted in said housing, an elongated impeller shaft connected to said impeller, mounted for limited free axial play and extending from said housing, a hollow drive shaft rotatably mounted adjacent said housing coaxially with said impeller shaft, with said impeller shaft turnably extending therethrough, a seal for the pump having a pair of sealing elements in sealing engagement, one of said elements being connected to said impeller shaft to be pressed in tighter sealing engagement with the other upon axial movement of said impeller shaft and means resiliently connecting said impeller and drive shafts at their end portions distal said impeller, and resiliently biasing said impeller shaft in an axial direction to tighten sealng engagement of said sealing elements.

2. A circulating pump according to claim 1 in which said hollow drive shaft is the drive shaft of an electric motor mounted adjacent said housing.

3. A circulating pump according to claim Z in which said means resiliently connecting said shafts is a coil spring connected at one end to said drive shaft and at the other to said impeller shaft, said coil spring being wound in the direction of rotation of said impeller.

4. A circulating pump according to claim 3 in which said sealing elements comprise a pair of seal rings coaxially positioned with respect to said impeller ,shaft in face-to-face sealing engagement with each other, with said impeller shaft extending therethrough, the seal ring adjacent said impeller being movable with the impeller and impeller shaft, the other seal ring being sealed to said housing.

5. A circulating pump according to claim 4 in which said coil spring is connected to a nut adjustably threaded on the end of said impeller shaft.

6. A circulating pump according to claim 5 in which said pump is a circulator for a hydronic heating system.

7. A circulating pump according to claim 1 in which said hollow drive shaft is the drive shaft of an electric motor removably mounted against said housing.

5 6 9. A circulating pump according to claim 1 in which References Cited said means resiliently connecting said shaft is a coil spring connected at one end to said drive shaft and at the other UNITED STATES PATENTS end to said impeiler shaft, said coil spring being wound 967,232 11/1910 Tyson 64-27 in the direction of rotation of said impeller and in which 5 1,979,146 10/1934 Davey 64 15 X said sealing elements comprise a pair of seal lrings co- 2,434,979 1/1948 Bel-gh 103 87 axially positioned with respect to said impeller shaft, with 2,868,438 1/1959 Gammon et al 230 117 said impeller shaft extending therethrough, said rings being forced in sealing engagement by compression of said ROBERT M WALKER Primmy Examiner coil spring. 

1. A CIRCULATING PUMP COMPRISING A HOUSING, AN IMPELLER ROTATABLY MOUNTED IN SAID HOUSING, AN ELONGATED IMPELLER SHAFT CONNECTED TO SAID IMPELLER, MOUNTED FOR LIMITED FREE AXIALLY PLAY AND EXTENDING FROM SAID HOUSING, A HOLLOW DRIVE SHAFT ROTATABLY MOUNTED ADJACENT SAID HOUSING COAXIALLY WITH SAID IMPELLER SHAFT, WITH SAID IMPELLER SHAFT TURNABLY EXTENDING THERETHROUGH, A SEAL FOR THE PUMP HAVING A PAIR OF SEALING ELEMENTS IN SEALING ENGAGEMENT, ONE OF SAID ELEMENTS BEING CONNECTED TO SAID IMPELLER SHAFT TO BE PRESSED IN TIGHTER SEALING ENGAGEMENT WITH THE OTHER UPON AXIAL MOVEMENT OF SAID IMPELLER SHAFT AND MEANS RESILIENTLY CONNECTING SAID IMPELLER AND DRIVE SHAFTS AT THEIR END PORTIONS DISTAL SAID IMPELLER, AND RESILIENTLY BIASING SAID IMPELLER SHAFT IN AN AXIAL DIRECTION TO TIGHTEN SEALING ENGAGEMENT OF SAID SEALING ELEMENTS. 